Josh Berkus wrote: [quoted out of order]
> Looking at your analyze, though, I think it's not the sort that's taking the
> time as it is that the full sorted entity_id column won't fit in work_mem.
> Try increasing it?
Yup, that indeed fixed this particular query since neither table was
> It still has to sort because the clustering isn't guarenteed to be 100%.
I guess I was contemplating whether or not there are some conditions
where it could be 100% (perhaps combined with Hannu's read only
> However, such sorts should be very quick as they have little work to do.
True, so long as the table can fit in work-mem. For much larger tables
IMHO it'd be nice to be able to simply do a seq-scan on them if there were
some way of knowing that they were sorted.
In response to
pgsql-performance by date
|Next:||From: Thomas F.O'Connell||Date: 2005-04-26 06:26:46|
|Subject: Re: pgbench Comparison of 7.4.7 to 8.0.2|
|Previous:||From: Dave Held||Date: 2005-04-25 22:41:41|
|Subject: Re: [HACKERS] Bad n_distinct estimation; hacks suggested?|